This invention relates to railroad cars, and more particularly, to an improved railroad flatcar construction employing single axle trucks.
Conventional railroad flatcars include a structural frame supported for movement over a pair of rails by a wheel truck at each end of the car. The car frame is suspended on the wheel trucks through springs, and is provided with means necessary to support and connect lading thereto. The railroad car to which the present invention relates is the type which is constructed to support and transport truck trailers.
Railroad flatcars of this type must be structurally strong. At the same time, it is desirable that such railroad cars be light weight and include the necessary torsional flexibility so that the wheels (of the wheel trucks) remain in proper contact with the rails. Also, it is desirable that single axle wheel trucks, rather than double axle wheel trucks, be employed which adds more importance to the torsional flexibility required to maintain the wheels in proper contact with the rails.
There is more than one commercially available single axle wheel truck construction available so that it is advantageous that the flatcar frame be adaptable for use with as many different wheel truck constructions as possible. Also, it is important that the flatcar frame remain stable on the wheel trucks and not be permitted to sway or the wheel trucks to oscillate relative to the car.
The present invention achieves the aforementioned goals by providing a railroad flatcar construction adapted for transporting truck trailers and the like, which is structurally sound and of a minimum weight, and is adapted for use with a variety of single axle wheel trucks. The flatcar includes a structural frame constructed to provide torsional flexibility about its length to help maintain the wheels in proper engagement with the rails, and which is constructed to limit and cushion movement of the car frame laterally of the wheel trucks and to dampen oscillation of the wheel trucks longitudinally relative to the car.